Infrastructure build and operational maintenance for a listed operating company's website replacement

What changed

• Scope
  Infrastructure for the entire website replacement
• Configuration management
  Codified as IaC with a Terraform module structure
• CDN / SSL
  Centralized with CloudFront + ACM

Challenge

A listed company's website replacement requires cutting over to the new foundation without stopping production operation. On top of that, the engagement was premised on continued operational maintenance support after the switchover. We were asked to set up a foundation that manages traffic, SSL certificates, and monitoring uniformly across multiple websites, and to build a structure that could respond to the fine adjustments that arise during the operations phase.

Approach

1. 01 Inventoried the configuration and operational rules of the existing sites and identified what could be shared
2. 02 Started from AWS VPC network design, clarifying traffic boundaries
3. 03 Managed the configuration with Terraform on a per-module basis (acm / cloudfront / ec2 / vpc / scheduler / cloudwatch)
4. 04 Centralized CDN and SSL certificates with CloudFront + ACM, cutting the operational load across multiple sites
5. 05 Built a staging environment in parallel, securing a verification window before the production cutover
6. 06 Continued to support operational maintenance after replacement, responding to the adjustments that arise during the operations phase

Key success factors

Per-module reuse

We modularized Terraform by resource type, lowering the cost of adding or changing sites.

Unified CDN and certificate management

We centralized the SSL certificates of multiple sites with CloudFront + ACM, structurally holding down operational load.

Staged production cutover

With a two-step staging-to-production setup, we switched over carefully without stopping production operation.

Support through the operational maintenance phase

We continued to support operations after replacement, maintaining a structure that feeds on-site adjustments back into the design side.

Solution

We built a unified AWS-based infrastructure with a Terraform module structure. We supported the effort end to end — from the production cutover plan at replacement through the operational maintenance phase. Centralized management with CloudFront + ACM structurally lowered the operational load across multiple sites, and we built a foundation that could respond to the ongoing fine adjustments after replacement.